The mass of the coaster car shown below is 250 kg. point 1 is 100.0 m above the ground. point 3 is 55 m above the ground. the speed at point 3 is 27.0 m/s. calculate the total mechanical energy of the system.

Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 x 10 7 n/c. what is the magnitude of the force on a calcium ion with charge +e? what is its acceleration? is it possible for a particle with the same charge as as calcium to have a different acceleration if placed at this location? what would change the acceleration: mass of the particle? diameter of the particle?